Question

Determinati multimile B={x|x€N*șix+1€D18}

Answer 1

X+1∈N*,X+1∈D18=(1,2,3,6,9,18)
⇒X+1=1⇒X=0,NU ESTE SOLUTIE
⇒X+1=2⇒X=2-1⇒X=1
⇒X+1=3⇒X=3-2⇒X=2
⇒X+1=6⇒X=6-1⇒X=5
⇒X+1=9⇒X=9-1⇒X=8
⇒X+1=18⇒X=18-1⇒X=17

Answer 2

x+1€D18.____D18={1,2,3,6,9,18}._____ C1:x+1=1=>x=0____________________ C2:x+1=2=>x=1____________________ C3:x+1=3=>x=2____________________ C4:x+1=6=>x=5____________________ C5:x+1=9=>x=8____________________ C6:x+1=18=>x=17__________________ x€{0,1,2,5,8,17}nN*=>x={1,2,5,8,17}___ B={1,2,5,8,17}